KR20200084607A - Method and apparatus for receiving downlink control channel for reducing power consumption of a terminal in wireless communication system - Google Patents

Abstract

The present invention relates to a communications method and system for converging a 5G communications system for supporting higher data rates than a 4G system with a technology for IoT. The present invention may be applied to intelligent services based on the 5G communications technology and the IoT-related technology, such as smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, security and safety-related services and the like. Also, the present invention relates to a method of a terminal in a wireless communications system and an apparatus for performing the same. The method comprises the following steps of: receiving configuration information of a physical downlink control channel (PDCCH) from a base station; monitoring downlink control information (DCI) having a specific format in a slot based on the configuration information of the PDCCH; checking whether the number of physical downlink shared channels (PDSCHs) received based on the DCI having the specific format in the slot is the number based on a PDSCH reception capability of the terminal; and in case that the number of the PDSCHs received based on the DCI having the specific format is the number based on the PDSCH reception capability of the terminal, stopping monitoring DCI having the specific format in the slot.

Description

METHOD AND APPARATUS FOR RECEIVING DOWNLINK CONTROL CHANNEL FOR REDUCING POWER CONSUMPTION OF A TERMINAL IN WIRELESS COMMUNICATION SYSTEM}

The present invention relates to a method and apparatus for efficient power management in a wireless communication system. In addition, the present invention relates to a downlink control channel receiving method and apparatus for reducing power consumption of a terminal in a wireless communication system.

Efforts have been made to develop an improved 5G communication system or a pre-5G communication system to meet the increasing demand for wireless data traffic after commercialization of the 4G communication system. For this reason, the 5G communication system or the pre-5G communication system is called a 4G network (Beyond 4G Network) communication system or an LTE system (Post LTE) system. To achieve high data rates, 5G communication systems are contemplated for implementation in the ultra-high frequency (mmWave) band (eg, 60 gigabit (60 GHz) band). In order to mitigate path loss of radio waves in the ultra-high frequency band and increase the transmission distance of radio waves, in 5G communication systems, beamforming, massive array multiple input/output (massive MIMO), full dimensional multiple input/output (FD-MIMO) ), array antenna, analog beam-forming, and large scale antenna technologies are being discussed. In addition, in order to improve the network of the system, in the 5G communication system, an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network , Device to Device communication (D2D), wireless backhaul, mobile network, cooperative communication, CoMP (Coordinated Multi-Points), and interference cancellation Technology development is being made. In addition, in the 5G system, advanced coding modulation (Advanced Coding Modulation (ACM)) Hybrid FSK and QAM Modulation (FQAM) and SSC (Sliding Window Superposition Coding), SWB (Advanced Coding Modulation, Filter Bank Multi Carrier), NOMA (non orthogonal multiple access), and SCMA (sparse code multiple access) are being developed.

Meanwhile, the Internet is evolving from a human-centered connection network where humans generate and consume information, to an Internet of Things (IoT) network that exchanges information between distributed components such as objects. Internet of Everything (IoE) technology, in which big data processing technology, etc. through connection to a cloud server, is combined with IoT technology is also emerging. In order to implement IoT, technical elements such as sensing technology, wired/wireless communication and network infrastructure, service interface technology, and security technology are required, and recently, a sensor network for connection between objects, a machine to machine (Machine to Machine) , M2M), MTC (Machine Type Communication) and other technologies are being studied. In the IoT environment, an intelligent IT (Internet Technology) service that collects and analyzes data generated from connected objects to create new values in human life may be provided. IoT is a field of smart home, smart building, smart city, smart car or connected car, smart grid, health care, smart home appliance, high-tech medical service through convergence and complex between existing IT (information technology) technology and various industries. It can be applied to.

Accordingly, various attempts have been made to apply a 5G communication system to an IoT network. For example, technologies such as sensor network, machine to machine (M2M), and machine type communication (MTC) are being implemented by techniques such as beamforming, MIMO, and array antenna, which are 5G communication technologies. will be. It may be said that the application of cloud radio access network (cloud RAN) as the big data processing technology described above is an example of 5G technology and IoT technology convergence.

In the 5G communication system, for the purpose of reducing the power consumption of the terminal, a method of adjusting whether to monitor the downlink control channel (Physical Downlink Control Channel) with L1 (Layer 1) signaling is discussed. The L1 signaling is a signal indicating that monitoring of the PDCCH of the terminal (which is referred to as a wake-up signal (WUS)) or a signal indicating not performing monitoring of the PDCCH (this is GTS (Go -to-sleep signal). For example, the base station may transmit the WUS to the terminal, and the terminal may perform monitoring of the PDCCH from the time after detecting the WUS. As another example, the base station may transmit the GTS to the terminal, and the terminal may not perform monitoring for the PDCCH from a time point after detecting the GTS for a specific time.

In various embodiments of the present invention, regardless of the low power mode indicator such as the WUS or GTS, the UE reports to the base station based on various capabilities of the UE, without affecting the PDSCH (physical downlink shared channel) reception of the UE. It is an object of the present invention to provide a method and apparatus for preventing power consumption of a terminal due to blind decoding of a PDCCH by stopping PDCCH blind decoding when a specific condition is satisfied.

According to an embodiment of the present invention, in a method of a terminal in a wireless communication system, receiving configuration information for a physical downlink control channel (PDCCH) from a base station, based on configuration information for the PDCCH, a specific format in a slot Monitoring downlink control information (DCI), determining whether the number of physical downlink shared channels (PDSCHs) received based on the DCI of the specific format in the slot is the number based on the PDSCH reception capability of the UE If the number of PDSCHs received based on the DCI of the format is a number based on the PDSCH reception capability of the terminal, it is possible to provide a method comprising the step of stopping monitoring for the DCI of the specific format in the slot. have.

In addition, according to an embodiment of the present invention, the UE receives configuration information for a physical downlink control channel (PDCCH) from a transceiver and a base station, and based on the configuration information for the PDCCH, DCI of a specific format in a slot downlink control information), and check whether the number of physical downlink shared channels (PDSCHs) received based on the DCI of the specific format in the slot is the number based on the PDSCH reception capability of the UE, and to the DCI of the specific format. If the number of PDSCHs received based on the number based on the PDSCH reception capability of the terminal, it is possible to provide a terminal including at least one processor that controls to stop monitoring for DCI of the specific format in the slot.

According to an embodiment of the present invention, a method and apparatus for efficient power management in a wireless communication system can be provided.

In addition, according to an embodiment of the present invention, a method and apparatus for receiving a downlink control channel for reducing power consumption of a terminal in a wireless communication system may be provided.

In addition, according to an embodiment of the present invention, without affecting PDSCH reception of the terminal based on the capability of the terminal, when a specific condition is satisfied based on the capability, PDCCH blind decoding is stopped to consume power of the terminal according to PDCCH monitoring Can be minimized.

1 is a diagram showing the basic structure of a time-frequency domain in 5G according to an embodiment of the present invention.
2 is a diagram illustrating a frame, subframe, and slot structure in 5G according to an embodiment of the present invention.
3 is a diagram illustrating an example of setting a bandwidth portion in 5G according to an embodiment of the present invention.
4 is a diagram illustrating an example of setting a control region of a downlink control channel in 5G according to an embodiment of the present invention.
5 is a diagram illustrating the structure of a downlink control channel in 5G according to an embodiment of the present invention.
FIG. 6 is a diagram illustrating the setting of search space sets for monitoring a downlink control channel in 5G according to an embodiment of the present invention.
7 is a diagram illustrating a PDCCH decoding method of a terminal according to the first embodiment of the present invention.
8 is a diagram illustrating a terminal procedure according to the first embodiment of the present invention.
9 is a diagram illustrating a PDCCH decoding method of a terminal according to a second embodiment of the present invention.
10 is a diagram illustrating a terminal procedure according to a second embodiment of the present invention.
11 is a diagram illustrating a PDCCH decoding method of a terminal according to a third embodiment of the present invention.
12 is a diagram illustrating a terminal procedure according to a third embodiment of the present invention.
13 is a block diagram showing the configuration of a terminal according to an embodiment of the present invention.
14 is a block diagram showing the configuration of a base station according to an embodiment of the present invention.

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description, when it is determined that a detailed description of a known function or configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. In addition, terms to be described later are terms defined in consideration of functions in the present invention, which may vary according to a user's or operator's intention or practice. Therefore, the definition should be made based on the contents throughout this specification.

In the following description of the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description will be omitted. Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

Terms used to identify a connection node used in the following description, terms referring to network objects, terms referring to messages, terms referring to interfaces between network objects, terms referring to various identification information Etc. are exemplified for convenience of explanation. Therefore, the present invention is not limited to the terms described below, and other terms indicating objects having equivalent technical meanings may be used.

For convenience of description below, the present invention uses terms and names defined in the 3GPP 3rd Generation Partnership Project Long Term Evolution (LTE) standard. However, the present invention is not limited by the terms and names, and may be applied to systems conforming to other standards. In the present invention, the eNB may be used in combination with the gNB for convenience of explanation. That is, a base station described as an eNB may indicate gNB.

The wireless communication system is beyond the initial voice-oriented service, for example, 3GPP's High Speed Packet Access (HSPA), Long Term Evolution (LTE) or Evolved Universal Terrestrial Radio Access (E-UTRA), LTE-Advanced Broadband radio that provides high-speed, high-quality packet data services such as (LTE-A), LTE-Pro, 3GPP2 High Rate Packet Data (HRPD), UMB (Ultra Mobile Broadband), and IEEE 802.16e. It is developing as a communication system.

As a representative example of the wideband wireless communication system, an LTE system adopts an Orthogonal Frequency Division Multiplexing (OFDM) method in a downlink (DL), and a single carrier frequency division multiple in SC (F-FDMA) in an uplink (UL). Access) method is adopted. Uplink refers to a radio link through which a user equipment (UE) or a mobile station (MS) transmits data or control signals to a base station (eNode B, or base station (BS)). A radio link that transmits data or control signals. In the multiple access method as described above, data or control information of each user is classified by assigning and operating so that time-frequency resources to be loaded with data or control information for each user do not overlap with each other, that is, orthogonality is established. do.

As a future communication system after LTE, that is, a 5G communication system must be able to freely reflect various requirements such as users and service providers, so services satisfying various requirements at the same time must be supported. Services considered for 5G communication systems include Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), and Ultra Reliability Low Latency Communication (URLLC). There is this.

eMBB aims to provide an improved data transfer rate than that supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, an eMBB should be able to provide a maximum data rate of 20 Gbps in the downlink and a maximum data rate of 10 Gbps in the uplink from the perspective of one base station. In addition, the 5G communication system should provide the maximum transmission speed, and at the same time, provide the increased user's actual perceived data rate. In order to satisfy these requirements, it is required to improve various transmission/reception technologies, including more advanced multi-input multi-output (MIMO) transmission technology. In addition, while the signal is transmitted using a maximum bandwidth of 20 MHz in the 2 GHz band used by current LTE, the 5G communication system requires 5G communication system by using a wider frequency bandwidth than 20 MHz in the 3-6 GHz or 6 GHz or higher frequency band. Data transmission speed can be satisfied.

At the same time, mMTC is being considered to support application services such as the Internet of Things (IoT) in 5G communication systems. In order to efficiently provide the Internet of Things, mMTC is required to support access of large-scale terminals within a cell, improve the coverage of the terminals, improve battery time, and reduce the cost of the terminals. The Internet of Things must be able to support a large number of terminals (eg, 1,000,000 terminals/km2) within a cell, as it is attached to various sensors and various devices to provide communication functions. In addition, the terminal supporting mMTC is more likely to be located in a shaded area that is not covered by a cell, such as the basement of a building, due to the nature of the service, and thus requires more coverage than other services provided by the 5G communication system. A terminal supporting mMTC should be configured with a low-cost terminal, and since it is difficult to frequently replace the battery of the terminal, a very long battery life time such as 10 to 15 years is required.

Finally, in the case of URLLC, it is a cellular-based wireless communication service used for a specific purpose (mission-critical). For example, remote control for robots or machinery, industrial automation, unmaned aerial vehicles, remote health care, emergency situations It is possible to consider services used for alerts, and the like. Therefore, the communication provided by URLLC must provide very low latency and very high reliability. For example, a service supporting URLLC must satisfy air interface latency less than 0.5 milliseconds, and at the same time, has a requirement of a packet error rate of 10-5 or less. Therefore, for a service supporting URLLC, a 5G system must provide a smaller transmit time interval (TTI) than other services, and at the same time, a design in which a wide resource is allocated in the frequency band to secure the reliability of the communication link. Is required.

Three services of 5G, eMBB, URLLC, and mMTC can be multiplexed and transmitted in one system. At this time, different transmission/reception techniques and transmission/reception parameters may be used between services to satisfy different requirements of each service.

Hereinafter, the frame structure of the 5G system will be described in more detail with reference to the drawings.

1 is a diagram illustrating a basic structure of a time-frequency domain, which is a radio resource domain in which data or a control channel is transmitted in a 5G system according to an embodiment of the present invention.

(일례로 12)개의 연속된 RE들은 하나의 자원 블록(Resource Block, RB, 104)을 구성할 수 있다. 서브프레임(110)은 1 ms 로 정의되고, 복수의 심볼들을 포함할 수 있다.In Fig. 1, the horizontal axis represents the time domain, and the vertical axis represents the frequency domain. The basic unit of resources in the time and frequency domain is a resource element (RE, 101), defined as 1 Orthogonal Frequency Division Multiplexing (OFDM) symbol 102 on the time axis and 1 subcarrier 103 on the frequency axis. Can be. In the frequency domain

(E.g., 12) consecutive REs may constitute one resource block (Resource Block, RB, 104). The subframe 110 is defined as 1 ms, and may include a plurality of symbols.

2 is a diagram illustrating a slot structure considered in a 5G system according to an embodiment of the present invention.

)=14). 1 서브프레임(201)은 하나 또는 다수 개의 슬롯(202, 203)으로 구성될 수 있으며, 1 서브프레임(201)당 슬롯(202, 203)의 개수는 부반송파 간격에 대한 설정 값

(204, 205)에 따라 다를 수 있다. 도 2의 일 예에서는 부반송파 간격 설정 값으로

=0(204)인 경우와

=1(205)인 경우가 도시되어 있다.

=0(204)일 경우(부반송파 간격이 15 kHz인 경우), 1 서브프레임(201)은 1개의 슬롯(202)으로 구성될 수 있고,

=1(205)일 경우(부반송파 간격이 30 kHz인 경우), 1 서브프레임(201)은 2개의 슬롯(203)으로 구성될 수 있다. 즉 부반송파 간격에 대한 설정 값

에 따라 1 서브프레임 당 슬롯 수(

)가 달라질 수 있고, 이에따라 1 프레임 당 슬롯 수(

)가 달라질 수 있다. 각 부반송파 간격 설정

에 따른

및

는 하기의 표 1로 정의될 수 있다. 2, an example of a structure of a frame (200), a subframe (Subframe, 201), and a slot (Slot, 202) is illustrated. One frame 200 may be defined as 10 ms. One subframe 201 may be defined as 1 ms, and thus one frame 200 may be composed of ten subframes 201 in total. One slot (202, 203) may be defined by 14 OFDM symbols (ie, the number of symbols per slot (

)=14). One subframe 201 may be composed of one or a plurality of slots 202 and 203, and the number of slots 202 and 203 per 1 subframe 201 is a set value for the subcarrier interval

(204, 205). In the example of FIG. 2, the subcarrier spacing is set.

=0(204) and

=1 (205) is shown.

= 0 (204) (if the subcarrier interval is 15 kHz), one subframe 201 may be composed of one slot 202,

= 1 (205) (in case the subcarrier interval is 30 kHz), one subframe 201 may be composed of two slots 203. That is, the setting value for the subcarrier interval

Depending on the number of slots per subframe (

) May vary, and accordingly, the number of slots per frame (

) May vary. Set spacing of each subcarrier

In accordance

And

Can be defined as Table 1 below.

[Table 1]

Next, the bandwidth part (BWP) setting in the 5G communication system will be described in detail with reference to the drawings.

3 is a diagram illustrating an example of setting for a bandwidth portion in a 5G communication system according to an embodiment of the present invention.

3 shows an example in which the terminal bandwidth 300 is set to two bandwidth portions, namely, the bandwidth portion #1 301 and the bandwidth portion #2 302. The base station may set one or a plurality of bandwidth portions to the terminal, and may set the following information for each bandwidth portion.

[Table 2]

In addition to the setting information, various parameters related to the bandwidth part may be set to the terminal. The information may be transmitted to the terminal by the base station through higher layer signaling, for example, radio resource control (RRC) signaling. At least one bandwidth portion among the set one or multiple bandwidth portions may be activated. Whether to activate the set bandwidth part may be semi-statically transmitted from the base station to the terminal through RRC signaling or dynamically transmitted through downlink control information (DCI).

The UE before the RRC connection may receive an initial bandwidth portion (Initial BWP) for initial access from a base station through a MIB (Master Information Block). More specifically, the UE may transmit a PDCCH for receiving system information (remaining system information; may correspond to RMSI or System Information Block 1; SIB1) required for initial access through the MIB in the initial access step. It is possible to receive setting information for a control resource set (CORESET) and a search space. The control area and the search space set by the MIB may be regarded as an identifier (ID) 0, respectively. The base station may notify the UE of the configuration information such as frequency allocation information, time allocation information, and numerology for the control region #0 through the MIB. In addition, the base station may notify the UE of the setting information for the monitoring period and occasion for the control region #0 through the MIB, that is, the setting information for the search space #0. The UE may regard the frequency region set as the control region #0 obtained from the MIB as an initial bandwidth portion for initial access. At this time, the identifier (ID) of the initial bandwidth portion may be regarded as 0.

The bandwidth portion supported by the 5G may be used for various purposes.

For example, when the bandwidth supported by the terminal is smaller than the system bandwidth, it may be supported by setting the bandwidth portion. For example, by setting the frequency location of the bandwidth portion to the terminal, the terminal can transmit and receive data at a specific frequency location within the system bandwidth.

As another example, for the purpose of supporting different numerology, the base station may set a plurality of bandwidth portions to the terminal. For example, in order to support data transmission and reception using a subcarrier spacing of 15 kHz and a subcarrier spacing of 30 kHz to a certain terminal, two bandwidth portions may be set to subcarrier spacings of 15 kHz and 30 kHz, respectively. Different bandwidth parts may be frequency division multiplexed, and when data is to be transmitted/received at a specific subcarrier interval, a bandwidth part set at a corresponding subcarrier interval may be activated.

As another example, for the purpose of reducing power consumption of the terminal, the base station may set a bandwidth portion having different sizes of bandwidth to the terminal. For example, if the terminal supports a very large bandwidth, for example, a bandwidth of 100 MHz, and always transmits/receives data with the corresponding bandwidth, it may cause very large power consumption. In particular, monitoring of an unnecessary downlink control channel with a large bandwidth of 100 MHz in a situation where there is no traffic is very inefficient in terms of power consumption. For the purpose of reducing the power consumption of the terminal, the base station may set a bandwidth portion of a relatively small bandwidth to the terminal, for example, a bandwidth portion of 20 MHz. In the absence of traffic, the UE can perform a monitoring operation in the 20 MHz bandwidth portion, and when data occurs, can transmit and receive data in the 100 MHz bandwidth portion according to the instructions of the base station.

In the method of setting the bandwidth part, the terminals before the RRC connection (Connected) can receive the configuration information for the initial bandwidth part (Initial Bandwidth Part) through the MIB (Master Information Block) and / or SIB in the initial access step have. In more detail, the UE is a Control Resource Set (DL) for a downlink control channel through which a Downlink Control Information (DCI) for scheduling a System Information Block (SIB) from a MIB of a PBCH (Physical Broadcast Channel) can be transmitted. CORESET). The bandwidth of the control region set as MIB may be regarded as an initial bandwidth portion, and the UE may receive a PDSCH through which SIB is transmitted through the set initial bandwidth portion. The initial bandwidth portion may be used for other system information (OSI), paging, and random access, in addition to the purpose of receiving the SIB. When the SIB received based on the MIB includes configuration information for the initial bandwidth portion, the initial bandwidth portion may be set based on the SIB.

Next, the SS (Synchronization Signal)/PBCH block in 5G will be described.

The SS/PBCH block means a physical layer channel block composed of a primary SS (PSS), a secondary SS (SSS), and a PBCH, and is specifically as follows.

-PSS: a signal that is a reference for downlink time/frequency synchronization, and provides some information of a cell ID.

-SSS: serves as a reference for downlink time/frequency synchronization, and provides remaining cell ID information not provided by PSS. Additionally, it can serve as a reference signal for demodulation of the PBCH.

-PBCH: Provides essential system information required for transmitting and receiving data channels and control channels of a terminal. The essential system information may include search space related control information indicating radio resource mapping information of a control channel, scheduling control information for a separate data channel transmitting system information, and the like.

-SS/PBCH block: The SS/PBCH block is composed of a combination of PSS, SSS, and PBCH. One or more SS/PBCH blocks may be transmitted within 5 ms time, and each SS/PBCH block transmitted may be identified by an index.

The UE can detect the PSS and SSS in the initial access step and decode the PBCH. The MIB can be obtained from the PBCH and the control region #0 can be set therefrom. The UE may perform monitoring for the control area #0 assuming that the selected SS/PBCH block and the DMRS transmitted in the control area #0 are QCL (quasi co-location). The terminal may receive system information as downlink control information transmitted from the control region #0. The terminal may obtain RACH (Random Access Channel) related configuration information necessary for initial access from the received system information. The UE may transmit a PRACH (Physical RACH) to the base station in consideration of the SS/PBCH index selected by the UE, and the base station receiving the PRACH may obtain information on the SS/PBCH block index selected by the UE. From this, the base station can know that the terminal has selected a block from each SS/PBCH block and monitors the control region #0 associated with it.

Next, downlink control information (DCI) in a 5G system will be described in detail.

Scheduling information for uplink data (or a physical uplink shared channel (PUSCH)) or downlink data (or a physical downlink shared channel (PDSCH)) in a 5G system is via DCI. It is transmitted from the base station to the terminal. The UE may monitor the DCI format for fallback and the DCI format for non-fallback for PUSCH or PDSCH. The countermeasure DCI format may consist of a fixed field selected between the base station and the terminal, and the non-preparation DCI format may include a configurable field.

The DCI may be transmitted through a physical downlink control channel (PDCCH), which is a physical downlink control channel, through a channel coding and modulation process. Cyclic redundancy check (CRC) is attached to the DCI message payload and the CRC is scrambled with a Radio Network Temporary Identifier (RNTI) corresponding to the identity of the terminal. Different RNTIs are used depending on the purpose of the DCI message, for example, UE-specific data transmission, power control command or random access response. That is, the RNTI is not explicitly transmitted, but is included in the CRC calculation process and transmitted. Upon receiving the DCI message transmitted on the PDCCH, the terminal checks the CRC using the allocated RNTI, and if the CRC check result is correct, the terminal can know that the corresponding message is transmitted to the terminal.

For example, DCI scheduling a PDSCH for system information (SI) may be scrambled with SI-RNTI. The DCI scheduling the PDSCH for the RAR (Random Access Response) message may be scrambled with RA-RNTI. The DCI scheduling the PDSCH for the paging message may be scrambled with P-RNTI. DCI notifying the SFI (Slot Format Indicator) may be scrambled with SFI-RNTI. DCI notifying TPC (Transmit Power Control) may be scrambled with TPC-RNTI. The DCI for scheduling the UE-specific PDSCH or PUSCH may be scrambled with C-RNTI (Cell RNTI).

DCI format 0_0 may be used as a DCI to prepare for scheduling PUSCH, and at this time, CRC may be scrambled with C-RNTI. DCI format 0_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 3]

DCI format 0_1 may be used as an unprepared DCI for scheduling PUSCH, and the CRC may be scrambled with C-RNTI. DCI format 0_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 4]

DCI format 1_0 may be used as a DCI to prepare for scheduling PDSCH, and at this time, CRC may be scrambled with C-RNTI. DCI format 1_0 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 5]

DCI format 1_1 may be used as an unprepared DCI for scheduling a PDSCH, and the CRC may be scrambled with C-RNTI. DCI format 1_1 in which CRC is scrambled with C-RNTI may include, for example, the following information.

[Table 6]

The DCI format 0_0, DCI format 1_0, and DCI format 2_2 and DCI format 2_3 described below have the same size (A) of the DCI message payload. DCI format 0_1, DCI format 1_1, DCI format 2_0 and DCI format 2_1, which will be described below, may have different DCI message payload sizes, respectively. That is, the size of the DCI message payload in DCI format 0_1 is B, the size of DCI message payload in DCI format 1_1 is C, the size of DCI message payload in DCI format 2_0 is D, and the DCI message payload in DCI format 2_1 is When the size is E, A, B, C, D, and E can all be set differently. Accordingly, the UE can monitor DCI formats by assuming sizes A, B, C, D, and E of up to five different DCI message payloads. Accordingly, when the UE monitors DCI formats having the size of all the DCI message payloads, power consumption according to blind decoding increases, and the DCI format having a specific DCI message payload size proposed in the embodiment of the present invention If the terminal can stop monitoring for, it is possible to prevent that much power consumption.

Hereinafter, a downlink control channel in a 5G communication system will be described in more detail with reference to the drawings.

4 is a diagram illustrating an example of a control region (Control Resource Set, CORESET) in which a downlink control channel is transmitted in a 5G wireless communication system according to an embodiment of the present invention. FIG. 4 shows an example in which two control regions (control region #1 401, control region #2 402) are set in the bandwidth portion 410 of the terminal on the frequency axis and one slot 420 on the time axis. Show. The control regions 401 and 402 may be set to a specific frequency resource 403 within the entire terminal bandwidth portion 410 on the frequency axis. As the time axis, one or more OFDM symbols may be set, and this may be defined as a control resource set duration (404). In the example of FIG. 4, control region #1 401 is set to a control region length of 2 symbols, and control region #2 402 is set to a control region length of 1 symbol.

The control region in 5G described above may be set by the base station to the UE through higher layer signaling (eg, system information, master information block (MIB), radio resource control (RRC) signaling). Setting a control region to a terminal means providing information such as a control region identifier, a frequency location of the control region, and a symbol length of the control region. For example, it may include the following information.

[Table 7]

In Table 7, tci-StatesPDCCH (simply referred to as TCI state) configuration information is one or a number of Synchronization Signal (SS)/PBCH (Physical Broadcast) related to a Quasi Co Located (QCL) with DMRS transmitted in the corresponding control area. Channel) may include information of a block index or a channel state information reference signal (CSI-RS) index.

5 is a view showing an example of a basic unit of time and frequency resources constituting a downlink control channel that can be used in 5G according to an embodiment of the present invention. According to FIG. 5, a basic unit of time and frequency resources constituting a control channel is called a resource element group (REG) 503, and the REG 503 is 1 OFDM symbol 501 on the time axis and 1 PRB on the frequency axis ( Physical Resource Block, 502), that is, it may be defined as 12 subcarriers. The downlink control channel allocation unit may be configured by concatenating the REG 503.

As illustrated in FIG. 5, when a basic unit to which a downlink control channel is allocated in 5G is called a control channel element (CCE), 1 CCE 504 may be composed of a plurality of REGs 503. Referring to the REG 503 shown in FIG. 5 as an example, the REG 503 may be composed of 12 REs, and if 1 CCE 504 is composed of 6 REGs 503, 1 CCE 504 is It means that it can be composed of 72 REs. When a downlink control region is set, the corresponding region may be composed of a plurality of CCEs 504, and a specific downlink control channel may be configured as one or a plurality of CCEs 504 according to an aggregation level (AL) in the control region. It can be mapped and transmitted. The CCEs 504 in the control area are divided into numbers, and the numbers can be assigned according to a logical mapping method.

The basic unit of the downlink control channel illustrated in FIG. 5, that is, REG 503, may include both REs to which DCI is mapped and a region to which DMRS 505 as a reference signal for decoding is mapped. As illustrated in FIG. 5, three DMRSs 505 may be transmitted in one REG 503.

The number of CCEs required to transmit the PDCCH can be 1, 2, 4, 8, or 16 depending on the aggregation level (AL), and the number of different CCEs allows link adaptation of the downlink control channel. Can be used to implement For example, when AL=L, one downlink control channel may be transmitted through L CCEs. The terminal needs to detect the signal without knowing the exact location information and AL for the downlink control channel, and has defined a search space indicating a set of CCEs for blind decoding. The search space is a set of downlink control channel candidates (Candidates) composed of CCEs that the UE should attempt decoding on a given aggregation level, and various aggregations that make one bundle with 1, 2, 4, 8, 16 CCEs Since there are levels, the terminal has a plurality of search spaces. The search space set may be defined as a set of search spaces at all set aggregation levels.

The search space can be classified into a common search space and a UE-specific search space. A certain group of terminals or all terminals may examine a common search space of the PDCCH in order to receive common cell control information such as dynamic scheduling or paging messages for system information. For example, PDSCH scheduling allocation information for transmission of SIB including cell operator information may be received by examining a common search space of the PDCCH. In the case of a common search space, since a certain group of terminals or all terminals must receive the PDCCH, it can be defined as a set of predetermined CCEs. The scheduling allocation information for the UE-specific PDSCH or PUSCH may be received by examining the UE-specific search space of the PDCCH. The terminal-specific search space may be terminal-specifically defined as a function of the identity of the terminal and various system parameters.

In 5G, parameters for the search space for the PDCCH may be set from the base station to the terminal by higher layer signaling (eg, SIB, MIB, RRC signaling). For example, the base station has a number of PDCCH candidate groups at each aggregation level L, a monitoring cycle for a search space, a monitoring occasion in a symbol unit in a slot for a search space, a search space type (common search space or terminal-specific search space), and a corresponding search space The combination of DCI format and RNTI to be monitored and control area index to monitor the search space can be set in the terminal. For example, it may include the following information.

[Table 8]

The base station may set one or a plurality of search space sets to the terminal according to the setting information. For example, the base station may set the UE to search space set 1 and search space set 2, and set DCI format A scrambled from X-RNTI in search space set 1 to be monitored in a common search space, and in search space set 2 DCI format B scrambled with Y-RNTI can be configured to be monitored in a UE-specific search space.

According to the setting information, one or more sets of search spaces may be present in the common search space or the terminal-specific search space. For example, search space set #1 and search space set #2 may be set as a common search space, and search space set #3 and search space set #4 may be set as terminal-specific search spaces.

In the common search space, the following combination of DCI format and RNTI can be monitored.

- DCI format 0_0/1_0 with CRC scrambled by C-RNTI, CS-RNTI, SP-CSI-RNTI, RA-RNTI, TC-RNTI, P-RNTI, SI-RNTI

- DCI format 2_0 with CRC scrambled by SFI-RNTI

- DCI format 2_1 with CRC scrambled by INT-RNTI

- DCI format 2_2 with CRC scrambled by TPC-PUSCH-RNTI, TPC-PUCCH-RNTI

- DCI format 2_3 with CRC scrambled by TPC-SRS-RNTI

In the terminal-specific search space, a combination of the following DCI format and RNTI can be monitored.

- DCI format 0_0/0_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

- DCI format 1_0/1_1 with CRC scrambled by C-RNTI, CS-RNTI, TC-RNTI

The RNTIs specified above may follow the following definitions and uses.

C-RNTI (Cell RNTI): UE-specific PDSCH scheduling purpose

TC-RNTI (Temporary Cell RNTI): UE-specific PDSCH scheduling purpose

CS-RNTI (Configured Scheduling RNTI): Semi-statically configured terminal-specific PDSCH scheduling purpose

RA-RNTI (Random Access RNTI): PDSCH scheduling in random access stage

P-RNTI (Paging RNTI): PDSCH scheduling for paging transmission

SI-RNTI (System Information RNTI): For PDSCH scheduling where system information is transmitted

INT-RNTI (Interruption RNTI): Used to inform whether or not the PDSCH is pucturing

TPC-PUSCH-RNTI (Transmit Power Control for PUSCH RNTI): For the purpose of indicating the power control command for PUSCH

TPC-PUCCH-RNTI (Transmit Power Control for PUCCH RNTI): To indicate the power control command for PUCCH

TPC-SRS-RNTI (Transmit Power Control for SRS RNTI): For indicating the power control command for SRS

The DCI formats specified above may follow the following definition.

[Table 9]

In 5G, the search space of the aggregation level L in the control area p and the search space set s can be expressed as the following equation.

[Equation 1]

In 5G, as a plurality of search space sets may be set with different parameters (eg, parameters in Table 8), the set of search space sets monitored by the UE at each time point may be different.

FIG. 6 is a diagram illustrating the setting of search space sets for monitoring a downlink control channel in 5G according to an embodiment of the present invention.

In FIG. 6, search space set #1 (601) is set to an offset 611 and a period 612 starting from slot 0 (600), and search space set #2 (602) is set to slot 0 (600). The offset 613 and the period 614 are set as the starting point, and the search space set #3 603 is set as the offset 615 and the period 616 starting from the slot 0 600. When the offsets and periods are different, the UE can monitor both the search space set #1 and the search space set #2 and the search space set #3 in a specific slot, and in a specific slot, two sets of the search space set You can monitor the search space of, and you can monitor one of search space set #1, search space set #2, and search space set #3 in a specific slot. In addition, in FIG. 6, the UE may receive a setting for an OFDM symbol in which a set of search spaces to be monitored is located in one slot 620, and FIG. 6 shows an example in which a search space set is located for every 2 OFDM symbols. have.

When a plurality of sets of search spaces are set for a terminal, the following conditions may be considered in a method for determining a set of search spaces that the terminal should monitor.

[Condition 1: Limit the maximum number of PDCCH candidates]

넘지 않는다.

는 서브캐리어 간격

kHz으로 설정된 셀에서의 슬롯 당 최대 PDCCH 후보군 수로 정의될 수 있으며, 하기 표로 정의될 수 있다. The number of PDCCH candidates that can be monitored per slot is

Do not exceed

Is the subcarrier spacing

It may be defined as the maximum number of PDCCH candidate groups per slot in a cell set to kHz, and may be defined as the following table.

Table 10

[Condition 2: Limit the maximum number of CCEs]

를 넘지 않는다.

는 서브캐리어 간격

kHz으로 설정된 셀에서의 슬롯 당 최대 CCE의 수로 정의될 수 있으며, 하기 표로 정의될 수 있다.The number of CCEs constituting the entire search space per slot (where the entire search space is the entire set of CCEs corresponding to a union region of a plurality of search space sets)

Does not exceed.

Is the subcarrier spacing

The maximum number of CCEs per slot in a cell set to kHz may be defined, and may be defined as the following table.

[Table 11]

For convenience of description, a situation that satisfies both of the above conditions 1 and 2 at a specific time point is defined as “condition A”. Therefore, not satisfying the condition A may mean not satisfying at least one of the conditions 1 and 2 above.

Depending on the set of search space sets of the base station, it may occur that the condition A described above is not satisfied at a specific time. If the condition A is not satisfied at a specific time, the terminal may select and monitor only a subset of the set of search spaces set to satisfy the condition A at the time, and the base station may transmit the PDCCH to the selected search space set.

The following method may be followed as a method of selecting some search spaces from among the entire set of search spaces.

[Method 1]

When the condition A for the PDCCH is not satisfied at a specific time (slot),

The terminal (or the base station) may preferentially select a set of search spaces in which the search space type is set as a common search space from among the set of search spaces existing at a corresponding time point over the set of search spaces set as a terminal-specific search space.

When all of the set of search spaces set as a common search space are selected (that is, when condition A is satisfied even after selecting all search spaces set as a common search space), the terminal (or the base station) is a terminal-specific search space. You can select the set of search spaces set to. At this time, when there are a plurality of search space sets set as terminal-specific search spaces, a search space set having a low search space set index may have a higher priority. In consideration of priority, UE-specific search space sets may be selected within a range in which condition A is satisfied.

In the 5G communication system, for the purpose of reducing the power consumption of the terminal, a method of adjusting whether to monitor or not monitoring a physical downlink control channel (PDCCH) by L1 (Layer 1) signaling is discussed. . The L1 signaling is a signal indicating that monitoring of the PDCCH of the terminal (which is referred to as a wake-up signal (WUS)) or a signal indicating not performing monitoring of the PDCCH (this is GTS (Go -to-sleep signal). For example, the base station may transmit the WUS to the terminal, and the terminal may perform monitoring of the PDCCH from the time after detecting the WUS. As another example, the base station may transmit the GTS to the terminal, and the terminal may not perform monitoring for the PDCCH from a time point after detecting the GTS for a specific time.

In various embodiments of the present invention, when the UE satisfies a specific condition without affecting PDSCH reception of the UE based on various capabilities of the UE independently of the low-power mode indicator such as WUS or GTS, the UE stops PDCCH blind decoding and performs PDCCH. To provide a method for preventing power consumption of a terminal due to blind decoding.

In various embodiments of the present invention, a method for monitoring a PDCCH of a UE is provided in consideration of the following PDSCH reception capability, RNTI reception capability, and PDCCH buffering capability. In the following embodiments, DCI format 1_1 is described as a specific DCI format, for convenience of description. However, the scope of various embodiments of the present invention is not limited to the DCI format 1_1. The scope of the present invention may be applied to all DCI formats capable of controlling the number of PDCCH monitoring/decoding according to the PDSCH reception capability, the RNTI reception capability, and the PDCCH storage capability.

In addition, in the following description, the first embodiment, the second embodiment, and the third embodiment are separately described for convenience of explanation, but each embodiment can be performed independently, and is performed by combining different embodiments. It is also possible. For example, the operation of monitoring the PDCCH with a combination of at least two of PDSCH reception capability, RNTI reception capability, and PDCCH storage capability may also be included in the scope of the present invention.

In an embodiment of the present invention, receiving the PDCCH may be interpreted as monitoring or decoding or receiving DCI on the PDCCH, and receiving PDSCH may be interpreted as decoding or receiving data scheduled through the DCI in the PDSCH. .

First, the UE's PDSCH reception capability will be described.

The PDSCH reception capability is defined as how many unicast PDSCHs the UE can receive in one slot.

The PDSCH reception capability is also related to how often the UE can decode the PDCCH monitoring occasion in one slot, that is, with what OFDM symbol period in one slot. [Table 12] below shows the capability of the UE for the PDCCH monitoring occasion in one slot.

Table 12

Accordingly, the UE reporting capability such as OFDM symbol period (eg, 2 OFDM symbol period at 15 KHz) of the PDCCH monitoring occasion according to each subcarrier spacing in 3-5a of [Table 12] through the upper signal. As described with reference to 620 of FIG. 6, they may receive higher information on which OFDM symbol to monitor the PDCCH in one slot from the base station.

Next, [Table 13] and [Table 14] show the capability of the UE on how many PDSCHs can be received in one slot.

[Table 13]

Table 14

As shown in 5-11 of [Table 13], UEs reporting capability to receive two unicast PDSCHs per slot can receive two unicast PDSCHs within one slot from a base station.

When monitoring the PDCCH of the terminal based on the above capability, the first embodiment for reducing power consumption of the terminal by stopping PDCCH decoding when a specific condition is satisfied will be described with reference to FIG. 7.

7 is a diagram illustrating a PDCCH decoding method of a terminal according to the first embodiment of the present invention.

7 shows that a PDSCH is scheduled by a PDCCH or DCI in one slot. At this time, the UE reporting the capabilities of 3-5a of [Table 12] and 5-11 of [Table 13] can perform PDCCH monitoring for every 2 OFDM symbols in 15KHz subcarrier spacing, within one slot. Two unicast PDSCHs can be received. When the terminal receives the upper information to perform monitoring of the PDCCH in every second OFDM symbol in one slot from the base station, every second, such as OFDM symbol #0 (720), OFDM symbol #2 (722) of FIG. PDCCH monitoring should be performed on OFDM symbols. In addition, when the terminal receives all K0 (the number of slots from the PDCCH receiving slot to the PDSCH receiving slot) from the base station to 0, the terminal determines that the PDSCH can be received in the slot receiving the PDCCH.

In OFDM symbol #0 720 of FIG. 7, the UE monitors the discovery area 701 to receive DCI 702, receives PDSCH 703 according to the scheduling of DCI 702, and OFDM symbol # At 2722, if the UE monitors the discovery area 711 and receives the DCI 712, and receives the PDSCH 713 according to the scheduling of the DCI 712, the UE according to the 5-11 capability report It is determined that the unicast PDSCH has been received, and it is no longer necessary to perform PDCCH monitoring to receive the unicast PDSCH in slot n (700). In this case, the terminal may stop monitoring for a specific DCI format. For example, the terminal may stop monitoring DCI format 1_1 corresponding to the unicast PDSCH. If the UE determines that it has not received all the unicast PDSCH numbers according to the 5-11 capability, it continues to monitor DCI format 1_1.

When the terminal receives all of the PDSCHs according to capability through the terminal procedure as described above, it is possible to reduce the waste of terminal power consumption required for the monitoring by stopping PDCCH monitoring for unicast PDSCH reception.

8 is a diagram illustrating a terminal procedure according to the first embodiment of the present invention.

In step 801, the UE may report at least one of the capability for the PDCCH monitoring period and the capability for the PDSCH reception described in FIG. 7 to the base station. At least one of the capabilities may be included in a terminal performance report message and transmitted to the base station. If the base station knows the information transmitted by the terminal through the operation 801, the operation 801 can be omitted. In step 802, the UE receives configuration information for the PDCCH. The configuration information for the PDCCH may include at least one of various information set by the base station to the terminal in order to receive the PDCCH in the present invention. In other embodiments, PDCCH configuration information may be interpreted the same. That is, when the base station transmits configuration information for the PDCCH to the terminal based on the capability reported from the terminal in step 801, the terminal receives the configuration information and performs PDCCH monitoring based on the configuration information.

In step 803, the UE attempts to receive the number of PDSCHs based on the capability in slot n. The UE checks whether a number of PDSCHs based on the capability has been received in slot n. Receiving PDSCH can be interpreted as receiving data through PDSCH. If the PDSCH reception of the number based on the capability is completed in step 803, in step 804, the UE may stop decoding for a specific DCI format in slot n. For example, the terminal stops decoding the unicast PDCCH, DCI format 1_1, in slot n. For example, if the UE conforms to the configuration information for the PDCCH, the UE should monitor the PDCCH in a predetermined symbol unit (for example, a PDCCH monitoring cycle), but as a result of the determination in step 803, the preset PDSCH reception count condition is satisfied PDCCH monitoring for a specific DCI format may be stopped regardless of configuration information for the PDCCH. In step 803, if the UE has not completed receiving the number of PDSCHs based on capability in the slot n, in step 805, the UE continues decoding the unicast PDCCH, DCI format 1_1, in slot n. In step 805, monitoring of the specific DCI format may be stopped when DCI monitoring of the specific format is performed based on PDCCH configuration information such as a PDCCH monitoring period and when the number of PDSCH reception based on the capability is completed. .

The operation may be performed according to the DCI format in units of slots. That is, if the above operation is performed on the first DCI format, the same operation may be performed on the second DCI format. Even if monitoring for the first DCI format is stopped in the slot because the above conditions are satisfied for the first DCI format, DCI monitoring for the second DCI format can be performed.

Next, when monitoring the PDCCH of the terminal, a second embodiment for reducing power consumption of the terminal by stopping PDCCH decoding when a specific condition is satisfied based on reception capability for RNTI will be described with reference to FIG. 9.

First, the reception capability for RNTI will be described.

In one PDCCH monitoring occasion, the UE can monitor PDCCHs for multiple RNTIs, and the UE can define the type and number of RNTIs that can be monitored in the specification.

The following [Table 15] lists definitions of RNTI reception types. In addition, [Table 16] shows the type and number of PDCCHs according to the RNTI that can be simultaneously received in one PDCCH monitoring occasion depending on whether the terminal is IDLE, RRC_INATIVE, RRC_CONNECTED, or whether the cell is Pcell, PSCell, or SCell. It is defined.

As shown in [Table 16], the UE may receive one DCI format 1_1 scrambled with C-RNTI scheduling DL-SCH in one PDCCH monitoring occasion.

In the above table, the following second embodiment is proposed based on the number of C-RNTI scrambled DCI formats 1_1 that the UE can receive in one PDCCH monitoring occasion.

Table 15

Table 16

9 is a diagram illustrating a PDCCH decoding method of a terminal according to a second embodiment of the present invention.

9 shows that a PDSCH is scheduled by a PDCCH, that is, DCI, in one PDCCH monitoring occasion. At this time, according to the above [Table 15], [Table 16], the UE is IDLE, RRC_INATIVE, RRC_CONNECTED, depending on whether the cell is Pcell, PSCell, SCell PDCCH according to different types and numbers of RNTI Monitoring can be performed.

For example, when the terminal is RRC_CONNECTED, the PDCCH configuration for monitoring the PDCCH for the SCell is received. The single article may monitor the discovery area 901 of the PDCCH monitoring occasion 904 for the SCell to receive the DCI 902 and the PDSCH 903 according to the scheduling of the DCI 902. If the UE has received the PDSCH, the UE determines that the unicast PDSCH scrambled with C-RNTI has been received according to [Table 15] and [Table 16], and PDCCH monitoring for PDCCH monitoring for receiving the unicast PDSCH is monitored. There is no need to perform it on occasion 904. Accordingly, the UE may stop monitoring DCI format 1_1 corresponding to another unicast PDSCH in the PDCCH monitoring occasion 904. If the UE determines that the number of unicast PDSCHs scrambled with C-RNTI has not been received according to [Table 15] and [Table 16], monitoring of DCI format 1_1 continues. In the above, DCI format 1_1 scrambled with C-RNTI is described as an example, but the scope of embodiments of the present invention is not limited thereto. If the number of DCI formats scrambled with another RNTI is satisfied within one PDCCH monitoring occasion 904 according to [Table 15] and [Table 16] (when the DCI of the number scrambled with the corresponding RNTI is received), the corresponding RNTI There is no need to perform PDCCH monitoring for DCI formats scrambled with. When the terminal receives all of the DCI format according to the RNTI reception capability through the terminal procedure as described above, it is possible to reduce the waste of terminal power required for the monitoring by stopping monitoring the PDCCH corresponding to the DCI format.

10 is a diagram illustrating a terminal procedure according to a second embodiment of the present invention.

In step 1001, the UE receives configuration information for the PDCCH. That is, the base station transmits configuration information for the PDCCH to the UE according to whether the cell to transmit the PDCCH to the UE is Pcell, PSCell, or SCell depending on whether the UE is IDLE, RRC_INATIVE, or RRC_CONNECTED. The terminal receives the setting information, and performs PDCCH monitoring based on the setting information.

In step 1002, the UE receives a number of PDCCHs based on the RNTI reception capability described in FIG. 9 in one PDCCH monitoring occasion. In step 1002, the UE checks whether a number of PDCCHs based on the RNTI reception capability has been received in one PDCCH monitoring occasion. Receiving the PDCCH can be interpreted as receiving DCI through the PDCCH. In step 1002, when the number of PDCCH receptions based on the RNTI reception capability is completed, in step 1003, the UE stops decoding the PDCCH in the PDCCH monitoring occasion. For example, the UE has completed the reception of a number of PDCCHs based on C-RNTI, and PDCCH monitoring may be stopped in DCI formats scrambled with C-RNTI in the corresponding PDCCH monitoring occasion. For example, there may be a plurality of PDCCH candidates in the PDCCH monitoring occasion of the search space, but if the PDCCH scrambled with the number of RNTIs based on the RNTI reception capability is completed in the PDCCH monitoring occasion, the PDCCH monitoring occasion of the PDCCH monitoring occasion In the remaining PDCCH candidates, monitoring of the PDCCH scrambled with the corresponding RNTI can be stopped. That is, when the PDCCH monitoring occasion is a time domain, monitoring of the PDCCH scrambled with the corresponding RNTI in another frequency domain of the corresponding time domain may be stopped. Accordingly, in the PDCCH monitoring occasion, only the PDCCH scrambled with the other RNTIs in the RNTI reception capability except the already received RNTI can be monitored to prevent the power consumption required to monitor the PDCCH corresponding to the RNTI received and excluded from the above. have. In step 1002, if the number of PDCCH reception based on the RNTI reception capability has not been completed, in step 1004, the UE continues decoding the PDCCH in the PDCCH monitoring occasion. If the PDCCH is continuously decoded to receive the number of PDCCHs based on the RNTI reception capability, the UE stops decoding the PDCCH at the PDCCH monitoring occasion.

The operation may be operated according to the DCI format in units of PDCCH monitoring occasion. That is, if the above operation is performed on the first RNTI, the same operation may be performed on the second RNTI. Even if monitoring for the DCI scrambled from the slot to the first RNTI is stopped by satisfying the above condition for the first RNTI, monitoring can be performed on the DCI scrambled with the second RNTI.

Next, when monitoring the PDCCH of the terminal, when a specific condition is satisfied based on the PDCCH buffering capability of the terminal capable of storing the PDCCH, the third embodiment for stopping PDCCH decoding to reduce power consumption of the terminal using FIG. 11 To explain.

First, the PDCCH buffering capability according to how much the UE can store the PDCCH will be described. In 5G (NR), it is defined in the standard that the UE does not need to store 16 or more PDCCHs scheduling unicast PDSCH received from slot 1 to slot 1 in a cell. Accordingly, the following third embodiment is proposed based on the PDCCH buffering capability.

11 is a diagram illustrating a PDCCH decoding method of a terminal according to a third embodiment of the present invention.

FIG. 11 shows that the PDSCH is scheduled by the PDCCH, that is, the DCI, in the slot n 1100. The terminal monitors the discovery area 1101 of the PDCCH monitoring occasion 1104 to receive the DCI 1102, and receives the PDSCH 1103 according to the scheduling of the DCI 1102. Further, the terminal may monitor the discovery area 1111 of the PDCCH monitoring occasion 1114 to receive the DCI 1112, and receive the PDSCH 1113 according to the scheduling of the DCI 1112. When the UE determines that PDCCH storage can no longer be performed according to the PDCCH buffering capability (or limit) 1120, the UE no longer needs to perform PDCCH monitoring for PDSCH reception. Accordingly, the UE may stop monitoring DCI format 1_0 and DCI format 1_1 scrambled with C-RNTI, CS-RNTI, and MCS-RNTI for scheduling of the PDSCH. Monitoring of DCI format 1_0 and DCI format 1_1 scrambled with C-RNTI, CS-RNTI, and MCS-RNTI for scheduling of the PDSCH when the UE determines that the number of PDCCHs according to the PDCCH buffering capability has not been received. Keep doing it. When the terminal receives all PDCCHs according to capability through the terminal procedure as described above, it is possible to reduce the waste of terminal power required for the monitoring by stopping the PDCCH monitoring.

12 is a diagram illustrating a terminal procedure according to a third embodiment of the present invention.

In step 1201, the UE receives configuration information for the PDCCH. That is, when the base station transmits the configuration information for the PDCCH to the terminal, the terminal receives the configuration information, and performs PDCCH monitoring based on the configuration information.

In step 1202, the UE receives the number of PDCCHs based on the capability corresponding to the PDCCH buffering limit in slot n. Receiving the PDCCH may be interpreted as receiving DCI through the PDCCH. In step 1202, the UE may check whether the number of PDCCHs corresponding to the PDCCH buffering limit is received in slot n. As a result of the check, if a corresponding number of PDCCHs is received, the process proceeds to step 1203, otherwise, the process proceeds to step 1204. When the number of PDCCHs corresponding to the PDCCH buffering limit in slot n is completed, in step 1203, the UE decodes DCI format 1_0 and DCI format 1_1 scrambled in slot n to C-RNTI, CS-RNTI, and MCS-RNTI. Stop. If the PDCCH reception of the number corresponding to the PDCCH buffering limit in the slot n is not completed, in step 1204, the UE performs scrambled DCI format 1_0, DCI format 1_1 of C-RNTI, CS-RNTI, or MCS-RNTI in step 1204. Decoding continues. When the number of PDCCHs corresponding to the PDCCH buffering limit in slot n is completed based on the decoding of the additional DCI format, the UE performs DCI format 1_0 scrambled to C-RNTI, CS-RNTI, and MCS-RNTI in slot n. The decoding of DCI format 1_1 can be stopped to prevent wasting power consumption.

In order to perform the above embodiments of the present invention, a transmitting unit, a receiving unit, and a control unit of a terminal and a base station are illustrated in FIGS. 13 and 14, respectively. A transmission and reception method of a base station and a terminal for applying a method of transmitting and receiving a downlink control channel and downlink control information in a 5G communication system corresponding to the above embodiment is shown, and a transmitter, a receiver, and a processing of the base station and the terminal to perform this Each addition should operate according to the embodiment.

Specifically, FIG. 13 is a block diagram showing the configuration of a terminal according to an embodiment of the present invention. As illustrated in FIG. 13, the terminal of the present invention may include a terminal processing unit 1301, a reception unit 1302, and a transmission unit 1303.

The terminal processing unit 1301 may control a series of processes in which the terminal can operate according to the above-described embodiment of the present invention. For example, the capability reporting of the terminal according to an embodiment of the present invention and the monitoring operation for the PDCCH accordingly may be differently controlled. The terminal processing unit 1301 may be referred to as a control unit or controller. Also, the terminal processing unit 1301 may include at least one processor.

The terminal processor 1301 receives configuration information for a physical downlink control channel (PDCCH) from a base station, monitors downlink control information (DCI) in a specific format in a slot based on the configuration information for the PDCCH, and in the slot It is checked whether the number of PDSCHs (physical downlink shared channels) received based on the DCI of the specific format is the number based on the PDSCH reception capability of the UE, and the number of PDSCHs received based on the DCI of the specific format is the If the number is based on the PDSCH reception capability, it can be controlled to stop monitoring for DCI of the specific format in the slot. Also, if the number of PDSCHs received based on the DCI of the specific format in the slot is smaller than the number based on the PDSCH reception capability of the terminal, the terminal processor 1301 monitors the PDCCH included in the configuration information for the PDCCH. Based on the can be controlled to monitor the DCI of the specific format. The DCI of the specific format may include DCI format 1_1.

In addition, the terminal processing unit 1301 checks whether the number of DCIs scrambled with a specific RNTI in a PDCCH monitoring occasion is a number based on RNTI reception performance, and DCI scrambled with a specific radio network temporary identifier (RNTI) in the PDCCH monitoring occasion. If the number received is the number based on RNTI reception performance, it may be controlled to stop monitoring of DCI scrambled with the specific RNTI in the PDCCH monitoring occasion. In addition, if the number of DCIs scrambled with the specific RNTI in the PDCCH monitoring occasion is less than the number based on RNTI reception performance, the terminal processing unit 1301 scrambles the DCI scrambled with the RNTI based on the configuration information for the PDCCH. It can be controlled to perform monitoring. The specific RNTI includes C-RNTI (cell-RNTI), and the DCI of the specific format may include DCI format 1_1.

In addition, the terminal processing unit 1301 checks whether the number of DCIs received in the slot corresponds to the PDCCH buffering limit, and if the number of DCIs received in the slot corresponds to the PDCCH buffering limit, the DCI in the slot It can be controlled to stop monitoring. The terminal processor 1301 may control to stop monitoring of DCI format 1_0 and DCI format 1_1 scrambled with modulation coding scheme-RNTI (CS-RNTI), CS-RNTI (configured scheduling-RNTI), and MCS-RNTI (modulation coding scheme-RNTI). . In addition, if the number of DCIs received in the slot is less than the number corresponding to the PDCCH buffering limit, the terminal processor 1301 may control to perform DCI monitoring in the slots based on configuration information for the PDCCH. .

The terminal receiving unit 1302 and the terminal are collectively referred to as a transmitting unit 1303 and may be referred to as a transceiver in an embodiment of the present invention. The transmitting and receiving unit may transmit and receive signals to and from a base station. The signal may include control information and data. To this end, the transmission/reception unit may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, an RF receiver that amplifies the received signal with low noise, and down-converts the frequency. In addition, the transmission/reception unit may receive a signal through a wireless channel, output the signal to the terminal processing unit 1301, and transmit a signal output from the terminal processing unit 1301 through the wireless channel.

14 is a block diagram showing the configuration of a base station according to an embodiment of the present invention. As illustrated in FIG. 14, the base station of the present invention may include a base station processor 1401, a receiver 1402, and a transmitter 1403.

The base station processor 1401 may control a series of processes so that the base station can operate according to the above-described embodiment of the present invention. For example, it is possible to differently control PDCCH setting and PDCCH transmission according to capability defined in the capability reporting and specification of the terminal according to an embodiment of the present invention. The base station processor 1401 may be referred to as a controller or controller. Also, the base station processing unit 1401 may include at least one processor.

The base station reception unit 1402 and the base station transmission unit 1403 may be collectively referred to as a transmission/reception unit in an embodiment of the present invention. The transmitting and receiving unit may transmit and receive signals to and from the terminal. The signal may include control information and data. To this end, the transmission/reception unit may include an RF transmitter that up-converts and amplifies the frequency of the transmitted signal, an RF receiver that amplifies the received signal with low noise, and down-converts the frequency. In addition, the transmission/reception unit may receive a signal through a wireless channel, output the signal to the base station processing unit 1401, and transmit a signal output from the base station processing unit 1401 through the wireless channel.

On the other hand, the embodiments of the present invention disclosed in the specification and drawings are merely to provide a specific example to easily explain the technical contents of the present invention and to help understand the present invention, and are not intended to limit the scope of the present invention. That is, it is obvious to those skilled in the art to which the present invention pertains that other modifications based on the technical spirit of the present invention can be implemented. In addition, each of the above embodiments can be operated in combination with each other as necessary.

Claims (20)

In the method of the terminal in the wireless communication system,
Receiving configuration information for a physical downlink control channel (PDCCH) from a base station;
Monitoring downlink control information (DCI) of a specific format in a slot based on configuration information for the PDCCH;
Checking whether the number of physical downlink shared channels (PDSCHs) received based on the DCI of the specific format in the slot is the number based on the PDSCH reception capability of the UE; And
And if the number of PDSCHs received based on the DCI of the specific format is the number based on the PDSCH reception capability of the terminal, stopping monitoring of the DCI of the specific format in the slot. According to claim 1,
If the number of PDSCHs received based on the DCI of the specific format in the slot is smaller than the number based on the PDSCH reception capability of the UE, DCI of the specific format based on the PDCCH monitoring period included in the configuration information for the PDCCH The method further comprises the step of monitoring. The method of claim 1, wherein the DCI of the specific format comprises DCI format 1_1. According to claim 1,
Checking whether the number of DCIs scrambled with a specific RNTI in the PDCCH monitoring occasion is the number based on RNTI reception performance; And
If the number of DCIs scrambled with a specific radio network temporary identifier (RNTI) in the PDCCH monitoring occasion is a number based on RNTI reception performance, further stopping the monitoring of DCI scrambled with the specific RNTI in the PDCCH monitoring occasion. Method comprising the. According to claim 4,
If the number of DCIs scrambled with the specific RNTI in the PDCCH monitoring occasion is less than the number based on RNTI reception performance, further monitoring the DCI scrambled with the RNTI based on configuration information for the PDCCH. Method comprising the. According to claim 4,
The method of claim 1, wherein the specific RNTI includes C-RNTI (cell-RNTI), and the DCI of the specific format includes DCI format 1_1. According to claim 1,
Checking whether the number of DCIs received in the slot corresponds to a PDCCH buffering limit;
And if the number of DCIs received in the slot corresponds to a PDCCH buffering limit, stopping the monitoring of DCIs in the slots. The method of claim 7,
If the number of DCI received in the slot is less than the number corresponding to the PDCCH buffering limit, further comprising the step of performing monitoring of the DCI in the slot based on the configuration information for the PDCCH. The method of claim 7, wherein the monitoring of DCI format 1_0 and DCI format 1_1 scrambled with C-RNTI, CS-RNTI (configured scheduling-RNTI), and MCS-RNTI (modulation coding scheme-RNTI) is stopped. . According to claim 1,
Further comprising the step of transmitting the terminal performance report information including the PDSCH reception capability of the terminal to the base station,
Method for setting the PDCCH information is generated based on the terminal performance report information. In the terminal,
Transceiver; And
Receives configuration information for a physical downlink control channel (PDCCH) from a base station, monitors downlink control information (DCI) in a specific format in a slot based on the configuration information for the PDCCH, and transmits configuration information to the DCI in the specific format in the slot. Based on the number of PDSCHs (physical downlink shared channel) received is determined based on the number of PDSCH reception capability of the terminal, the number of PDSCH received based on the DCI of the specific format is the number based on the PDSCH reception capability of the terminal If so, the terminal including at least one processor that controls to stop monitoring the DCI of the specific format in the slot. The method of claim 11, wherein the at least one processor,
If the number of PDSCHs received based on the DCI of the specific format in the slot is smaller than the number based on the PDSCH reception capability of the UE, DCI of the specific format based on the PDCCH monitoring period included in the configuration information for the PDCCH Terminal characterized in that to control to monitor. 12. The terminal of claim 11, wherein the DCI of the specific format includes DCI format 1_1. The method of claim 11, wherein the at least one processor,
In the PDCCH monitoring occasion, check whether the number of DCIs scrambled with a specific RNTI is the number based on RNTI reception performance, and the number of DCIs scrambled with a specific radio network temporary identifier (RNTI) in the PDCCH monitoring occasion is RNTI reception performance If the number is based on, the terminal characterized in that the control to stop monitoring of the DCI scrambled with the specific RNTI in the PDCCH monitoring occasion. 15. The method of claim 14, The at least one processor,
If the number of DCI scrambled with the specific RNTI in the PDCCH monitoring occasion is less than the number based on RNTI reception performance, controlling to perform monitoring of DCI scrambled with the RNTI based on configuration information for the PDCCH Terminal characterized by. The method of claim 14,
The specific RNTI includes a cell-RNTI (C-RNTI), and the DCI of the specific format includes a DCI format 1_1. The method of claim 11, wherein the at least one processor,
Checking whether the number of DCIs received in the slot corresponds to the PDCCH buffering limit, and if the number of DCIs received in the slot corresponds to the PDCCH buffering limit, controlling to stop monitoring the DCI in the slot Terminal characterized by. The method of claim 17, wherein the at least one processor,
If the number of DCI received in the slot is less than the number corresponding to the PDCCH buffering limit, the terminal characterized in that the control to perform the monitoring of the DCI in the slot based on the configuration information for the PDCCH. The method of claim 17, wherein the at least one processor,
A terminal characterized in controlling to stop monitoring of DCI format 1_0 and DCI format 1_1 scrambled with C-RNTI, CS-RNTI (configured scheduling-RNTI), and MCS-RNTI (modulation coding scheme-RNTI). The method of claim 11, wherein the at least one processor,
The terminal performance report information including the PDSCH reception capability of the terminal is transmitted to the base station,
A terminal characterized in that the configuration information for the PDCCH is generated based on the terminal performance report information.

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